Melanie M. Frigault

The MET inhibitor AZD6094 (Savolitinib, HMPL-504) induces regression in papillary renal cell carcinoma patient derived xenograft models

Purpose: Papillary renal cell carcinoma (PRCC) is the second most common cancer of the kidney and carries a poor prognosis for patients with nonlocalized disease. The HGF receptor MET plays a central role in PRCC and aberrations, either through mutation, copy number gain, or trisomy of chromosome 7 occurring in the majority of cases. The development of effective therapies in PRCC has been hampered in part by a lack of available preclinical models. We determined the pharmacodynamic and antitumor response of the selective MET inhibitor AZD6094 in two PRCC patient-derived xenograft (PDX) models. Experimental Design: Two PRCC PDX models were identified and MET mutation status and copy number determined. Pharmacodynamic and antitumor activity of AZD6094 was tested using a dose response up to 25 mg/kg daily, representing clinically achievable exposures, and compared with the activity of the RCC standard-of-care sunitinib (in RCC43b) or the multikinase inhibitor crizotinib (in RCC47). Results: AZD6094 treatment resulted in tumor regressions, whereas sunitinib or crizotinib resulted in unsustained growth inhibition. Pharmacodynamic analysis of tumors revealed that AZD6094 could robustly suppress pMET and the duration of target inhibition was dose related. AZD6094 inhibited multiple signaling nodes, including MAPK, PI3K, and EGFR. Finally, at doses that induced tumor regression, AZD6094 resulted in a dose- and time-dependent induction of cleaved PARP, a marker of cell death. Conclusions: Data presented provide the first report testing therapeutics in preclinical in vivo models of PRCC and support the clinical development of AZD6094 in this indication. Clin Cancer Res; 21(12); 2811–9. ©2015 AACR.

Biomarker-Based Phase II Trial of Savolitinib in Patients With Advanced Papillary Renal Cell Cancer

Purpose Patients with advanced papillary renal cell carcinoma (PRCC) have limited therapeutic options. PRCC may involve activation of the MET pathway, for example, through gene amplification or mutations. Savolitinib (AZD6094, HMPL-504, volitinib) is a highly selective MET tyrosine kinase inhibitor. We report results of a single-arm, multicenter, phase II study evaluating the safety and efficacy of savolitinib in patients with PRCC according to MET status. Patients and Methods Patients with histologically confirmed locally advanced or metastatic PRCC were enrolled and received savolitinib 600 mg orally once daily. MET-driven PRCC was defined as any of the following: chromosome 7 copy gain, focal MET or HGF gene amplification, or MET kinase domain mutations. Efficacy was assessed according to MET status. Safety, toxicity, and patient-reported health-related quality-of-life outcomes were assessed in all patients. Results Of 109 patients treated, PRCC was MET driven in 44 (40%) and MET independent in 46 (42%); MET status was unknown in 19 (17%). MET-driven PRCC was strongly associated with response; there were eight confirmed partial responders with MET-driven disease (18%), but none with MET-independent disease ( P = .002). Median progression-free survival for patients with MET-driven and MET-independent PRCC was 6.2 months (95% CI, 4.1 to 7.0 months) and 1.4 months (95% CI, 1.4 to 2.7 months), respectively (hazard ratio, 0.33; 95% CI, 0.20 to 0.52; log-rank P < .001). The most frequent adverse events associated with savolitinib were nausea, fatigue, vomiting, and peripheral edema. Conclusion These data show activity and tolerability of savolitinib in the subgroup of patients with MET-driven PRCC. Furthermore, molecular characterization of MET status was more predictive of response to savolitinib than a classification based on pathology. These findings justify investigating savolitinib in MET-driven PRCC.

Are Companion Diagnostics Useful

We define a companion diagnostics (CDx)5 test as any diagnostic tool that guides the selection of patient treatment. In the US, these tests include diagnostics cleared by the Food and Drug Administration (FDA), as well as laboratory-developed tests (LDTs) run in CLIA-accredited laboratories. The answer to the titles question is obviously in the affirmative. We discuss the growing need to improve, accelerate, and standardize oncology CDx that benefit patients. Recent advances in our understanding of the mutational landscape of cancers have led to the rapid development of targeted therapies for pathogenomic targets. At the same time, advances in next-generation sequencing (NGS) have revealed the complexity of heterogeneous cancers. With the fast pace of change occurring in clinical oncology, flexible approaches to CDx development are needed while test accuracy is maintained for delivering precision medicine to patients. The remarkable efficacies of new targeted therapies have recently changed the paradigm for oncology to one of matching the right patient with the right therapy (1). This approach requires robust laboratory testing of patient samples. FDA-cleared tests exist for a limited number of markers (Table 1). In contrast, LDTs developed in CLIA-certified laboratories are used for >2000 genetic tests (2). LDTs are currently used in oncology for patient care and in clinical trials, which are now evaluating >500 agents targeting >100 genomic alterations. View this table: Table 1. Select list of CDx used for selection of targeted therapies.a The recent success in the development of 2 targeted therapies, crizotinib and vemurafenib, exemplifies the CDx process in which the FDA has co-cleared a diagnostic test (3, 4). The development of the CDx included analytical validation and elements of quality systems (good manufacturing practice, design control, personnel, software, instrumentation, and other parameters) as critical components of the regulatory package. The tests were used to recruit patients to pivotal phase II trials for the presence of the mutation/gene fusion. The …

Abstract 1150: Targeting MET Exon 14 mutations with the selective small molecule inhibitor Savolitinib

Alterations in the MET oncogene occurs across a broad range of tumor indications. Amplification or mutations in MET lead to increased activity of downstream pathways including PI3K and MAPK, eventually resulting in tumor formation. Several small molecule inhibitors are currently in clinical trials, including the selective inhibitor Savolitinib (HMP-504, Volitinib, AZD6094), which shows single digit nanomolar activity in MET-amplified cell lines. Newly emerging data suggest mutations in MET causing complete skipping of Exon 14 occur in approximately 4% of non-small cell lung cancer (NSCLC), and are more rare in other indications [1, 2]. MET exon 14 skipping mutations were shown to be mutually exclusive from EGFRm, ALK and KRAS and can occur in the context of MET gene amplification [3]. Exon 14 harbors the CBL binding site (Y1003), which is critical for receptor degradation after binding of its ligand, HGF, and suppression of downstream signaling events. Clinical trial results with less potent, pan RTK inhibitors Crizotinib (31nM GI50 vs 3nM for Savolitinib) and Cabozantinib show promising early results, but fall short in long term responses. Therefore, better therapies targeting MET are needed. Human cell line models with Exon 14 deletions are rare. Therefore, we used engineered cell lines to test the effect of Savolitinib on these mutations. To do this, we expressed MET-Y1003F mutants in NIH-3T3 and HEK293T cells. We found that Savolitinib potently inhibited phospho-MET in both models expressing this mutant (100% phospho-MET inhibition). In addition, we tested whether or not Savolitinib could inhibit HGF-dependent signaling and growth of a NSCLC cell line, NCI-H596. In the presence of FBS (10%), Savolitinib had no effect on the growth rate of these cells, however was highly efficient at blocking HGF-dependent growth in the absence of FBS. To test the effect of this mutation in the background of amplification, we also tested the gastric cancer cell line Hs746T, which harbors exon 14 skipping in addition to MET amplification. Savolitinib was highly efficacious at blocking the growth of this cell line. Future studies are aimed at looking at the in vivo effect of Savolitinib targeting exon 14 mutants. These data provide a platform of evidence for using Savolitinib to target exon 14 mutant MET in patients. 1. Paik, P.K., et al., Response to MET inhibitors in patients with stage IV lung adenocarcinomas harboring MET mutations causing exon 14 skipping. Cancer Discov, 2015. 5(8): p. 842-9. 2. Frampton, G.M., et al., Activation of MET via diverse exon 14 splicing alterations occurs in multiple tumor types and confers clinical sensitivity to MET inhibitors. Cancer Discov, 2015. 5(8): p. 850-9. 3. Cancer Genome Atlas Research, N., Comprehensive molecular profiling of lung adenocarcinoma. Nature, 2014. 511(7511): p. 543-50. Citation Format: Evan Barry, Elizabeth Maloney, Ryan Henry, Alexandra Borodovsky, Edwin Clark, Melanie Frigault, Michael Zinda, Celina D’Cruz. Targeting MET Exon 14 mutations with the selective small molecule inhibitor Savolitinib. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1150.

Abstract 1477: Pharmacodynamic response and anti-tumor activity of the MET inhibitor AZD6094 in papillary renal cell carcinoma patient derived xenograft models

Papillary renal cell carcinoma (PRCC) is the second most common cancer of the kidney and carries a poor prognosis for patients with non-localized disease. The central role of the hepatocyte growth factor (HGF) receptor MET in PRCC has been explored, demonstrating that MET aberrations, either through mutation, copy number gain, or trisomy of chromosome 7 (the location of MET and HGF) occur in the majority of PRCC cases. We sought to evaluate AZD6094 (HMPL-504), a potent and selective small molecule MET kinase inhibitor, in this disease setting. However, the development of effective therapies targeting MET and other targets in PRCC has been hampered in part by a lack of available preclinical models to test novel targeted therapies. Here we describe for the first time the pharmacodynamic (PD) response and anti-tumor activity of the selective MET inhibitor AZD6094 in two preclinical patient derived xenograft (PDX) models of PRCC (RCC-43b and RCC-47). Both PDX models have increased MET copy number of 8 and 9 copies by FISH in RCC-43b, and RCC-47 respectively, and robust MET protein staining by IHC. AZD6094 treatment resulted in dose dependent anti-tumor responses reaching ∼85% tumor growth inhibition (TGI) when dosed at 2.5 mg/kg daily (qd), stasis when dosed 10 mg/kg qd, and ∼20% regression when dosed at 25 mg/kg qd in the RCC-43b model and ∼63% TGI, ∼89% TGI, ∼64% regression, and ∼96% regression in the RCC-47 model when dosed 0.5, 2.5, 10, and 25 mg/kg qd respectively. The standard of care for RCC, sunitinib, showed no activity in RCC-43b when dosed at 10 mg/kg qd (∼10% TGI, p>0.05 vs vehicle) and ∼60% TGI when dosed at 80 mg/kg qd. Pharmacodynamic analysis of RCC-47 tumors revealed that two hours after an acute dose of AZD6094 pMET levels were reduced >95% at all dose levels tested (0.5 - 25 mg/kg). Eight hours after dosing, pMET levels returned to ∼50% in the 0.5 and 2.5 mg/kg dose groups whereas pMET was still inhibited >90% in the 10 and 25 mg/kg dose groups indicating that the duration of target inhibition was dose related. AZD6094 inhibited multiple signaling nodes including MAPK, PI3K, and EGFR. Finally, at doses that induced tumor regression, AZD6094 resulted in a dose and time dependent induction of cleaved PARP, a marker of cell death. The finding that lower, sub-optimal doses of AZD6094 showed return of pMET 8 hours after a single administration, raised the question whether splitting the dose over a longer duration would increase anti-tumor activity. Indeed, twice a day dosing (bid, 8;16 hours) of AZD6094 at 1.25 mg/kg was more efficacious than daily administration of 2.5 mg/kg resulting in 8% regression compared to 89% TGI (p Citation Format: Alwin Schuller, Evan Barry, Rhys Jones, Melanie Frigault, Garry Beran, Ryan Henry, David Linsenmayer, Maureen Hattersley, Aaron Smith, Joanne Wilson, Ammar Adam, Michael Zinda, Corinne Reimer, Stephen Fawell, Edwin Clark, Celina D9Cruz. Pharmacodynamic response and anti-tumor activity of the MET inhibitor AZD6094 in papillary renal cell carcinoma patient derived xenograft models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1477. doi:10.1158/1538-7445.AM2015-1477

Abstract CT305: Phase I studies of a selective cMet inhibitor AZD6094 (HMPL504/volitinib) in patients with advanced solid tumors

Background: Volitinib is a selective oral small molecule inhibitor of cMet kinase, which has demonstrated potent in vivo inhibitory effects on a variety of human tumor xenografts. Methods: Two phase I dose-escalation studies have been conducted in Australia (AU) and China (CN) in parallel to determine the maximum tolerated dose (MTD) or phase II Recommended Dose (P2RD), to evaluate pharmacokinetics (PK) profile, and to assess antitumor activity of Volitinib. Treatment was given orally in 21-day cycles until disease progression or unacceptable toxicity. Results: By July 2014 both studies completed dose-escalation phase. A total of 61 patients were enrolled (40 in AU and 21 in CN). Patients were treated with daily (QD) volitinib from 100mg to 1000mg or twice daily (BID) from 300 mg to 600mg. Median age at baseline was 63 years, and 60% patients were male in the AU study; whereas median age was 53 years, and 57% patients were male in the CN study. In both studies, the most common treatment related adverse events included nausea, vomiting, fatigue, peripheral edema and decreased appetite, mostly of grade (G) 1/2. Four patients experienced 5 dose limiting toxicities (DLTs) in the AU study: 1 G3 abnormal liver function test at 600mg QD, 1 G3 fatigue at 800mg QD, and 2 G3 fatigues and 1 G3 headache at 1000mg QD. One DLT of G3 fatigue at 600mg BID was reported in the CN study. The MTD for the QD regimen was identified as 800mg whereas the MTD for the BID regimen had not been reached in either study. 500mg BID was determined to be the P2RD as monotherapy based on the favorable benefit/risk profile demonstrated in both studies. In the AU study, 2 patients in the 600mg QD cohort and 1 patient in 1000mg QD cohort achieved partial response (PR). All 3 responders were papillary renal cell carcinoma patients. Two of the 3 responders remain PR with volitinib treatment of approximately 10 and 18 months respectively by July 2014. One CRC patient at 600mg QD achieved a 29% tumor reduction. Tumor sample analysis showed that all responders had both MET gene copy number increase (Chr7 gains or Met gene amplification) and high MET protein expression. Volitinib was rapidly absorbed with Tmax around 2∼4 hours and rapidly eliminated with half-life around 3∼7 hours in both studies. Both Cmax and AUC were roughly dose-proportional up to 800 mg QD and 500 mg BID. No obvious accumulation was found after 21-day of continuous QD or BID dosing. Drug exposure did not show racial difference between Caucasian and Asian patients. Conclusions: Volitinib was well tolerated up to 800 mg QD and 600 BID with acceptable safety profile. 500mg BID was determined to be the P2RD as monotherapy. Preliminary efficacy data demonstrated promising anti-tumor activity in patients with Met gene copy number increase or high protein expression. Volitinib demonstrated linear PK profile without marked drug accumulation. Further clinical studies are warranted. Citation Format: Ye Hua, Lin Shen, Hui Gan, Jason Lickliter, Michael Millward, Jianming Xu, Jian Wang, Yang Sai, Weiguo Su, Melanie M. Frigault, Chuan Qi. Phase I studies of a selective cMet inhibitor AZD6094 (HMPL504/volitinib) in patients with advanced solid tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT305. doi:10.1158/1538-7445.AM2015-CT305

Abstract 761: Changing the paradigm for treating drug resistance in NSCLC: Novel combinations of AZD6094, a selective MET inhibitor, and an irreversible, selective (EGFRm/T790M) EGFRTKI, AZD9291

Aberrant receptor tyrosine kinase (RTK) signaling is a well-documented driver of disease onset and progression across myriad cancer types, where the MET RTK contributes to tumor progression, maintenance and resistance to targeted therapies. Here we explore the therapeutic potential of AZD6094, a highly potent and selective MET inhibitor, in EGFR mutant (EGFRm) non-small cell lung cancer (NSCLC). Although many EGFRm NSCLC patients receiving first-line EGFR Tyrosine Kinase Inhibitors (TKI) benefit from therapy initially, the majority of patients will acquire resistance in 9-14 months1,2. Of this patient population, ∼10-15% of patients with emerging resistance to early generation EGFRm-TKI will have MET amplification3. Using xenograft models (HCC827) of resistance to erlotinib or gefitinib, both first-generation EGFRm-TKI, we assessed the efficacy of AZD6094 in models with varying copy number gain for MET. We demonstrate that the combination of AZD6094 with gefitinib, or AZD9291, an irreversible, selective (EGFRm/T790M) EGFR TKI, results in tumor growth inhibition (TGI) of >100% in 3 models (HCC827-ER1, PCS030 clone 1 and 2)4, suggesting that the combination is necessary and sufficient to address acquired resistance due to MET gene amplification. Moreover, we explore efficacy of AZD6094 in models representative of resistance to first-line treatment with EGFRm-TKIs, harboring MET amplification and T790M EGFR mutations. In NCI-H820 xenografts (EGFRm/T790M/MET), we demonstrate for the first time that combining MET and EGFRm/T790M TKIs (AZD6094 with AZD9291) induces tumor regressions (TGI% >100%, 94% regressions) and the loss of palpable tumors in 5/7 animals as compared to AZD9291 (TGI 48%) or AZD6094 treatment alone (TGI >100%). Pharmacodynamic analysis of tumor lysates demonstrated potent and durable inhibition of pMET in all AZD6094 treatment groups. Due to the clinical importance of understanding acquired resistance to targeted TKIs, we then generated a model of resistance to AZD6094 in MET-amplified NSCLC NCI-H1993 cells and analyzed several resistant clones (H1993R). Interestingly, MET phosphorylation remains strongly inhibited in AZD6094-treated H1993R cells, while EGFR protein expression is upregulated and leads to co-dependency between both pathways. Enhanced expression and phosphorylation of EGFR, as well as AKT, MEK and ERK activation were commonly observed in H1993R cells. Taken together, our data support the potential of AZD6094 as a novel combination therapy for MET-driven NSCLC in the context of EGFRm TKI resistance, and highlight the clinical relevance of EGFR and MET signaling in the context of emerging TKI resistance mechanisms and coordinated pathways. 1. Mok et al. N Engl J Med 2009;361:947-957. 2. Rosell et al. Lancet Oncol 2012;13:239-246. 3. Engelman et al. Science 2007;316:1039-1043. 4. Models from Precos Ltd Citation Format: Celina D9Cruz, Evan Barry, Ryan Henry, Lillian Castriotta, Alwin Schuller, Garry Beran, Susan Ashton, Cath Eberlein, Corinne Reimer, Melanie Frigault, Michael Zinda, Darren Cross, Stephen Fawell. Changing the paradigm for treating drug resistance in NSCLC: Novel combinations of AZD6094, a selective MET inhibitor, and an irreversible, selective (EGFRm/T790M) EGFRTKI, AZD9291. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 761. doi:10.1158/1538-7445.AM2015-761

Is target validation all we need

Targeted therapy for cancer treatment has required a shift in drug development approaches from broad treatment with chemotherapies, to the development of precision medicines that are specific for clinical targets. Cancer biology is widely studied and translating these findings into efficacious targeted therapies requires more than just target validation. Targets identified pre-clinically must be reproducible in other models that harbor the target. In addition, the extent and duration with which the target is modulated is at times essential for efficacy. Further, not only the target is of focus but also any inherent feedback mechanisms or mechanisms of acquired resistance should be understood to optimize chemistry of agents in development to target the tumor biology and to inform on combination approaches. Another element of a target that will likely contribute to successful clinical validation include the impact of target intra-tumor and inter-tumor heterogeneity on clinical efficacy. Taken together, to answer the question Is target validation all we need? We highlight a few elements of tumor biology and drug chemistry that if understood, may increase the successful clinical validation of new targets and therefore provide more targeted treatment options for this disease.